This clinical report presents a technique to reconstruct extensively resected mandibles using a combination of autologous bone grafts and additive manufacturing techniques. Mandibular defects, often arising from trauma, tumors, or congenital anomalies, can severely impact both function and aesthetics. Conventional reconstruction methods have their limitations, often resulting in suboptimal outcomes. In these reports, we detail clinical cases where patients with different mandibular defects underwent reconstructive surgery. In each instance, autologous grafts were harvested to ensure the restoration of native bone tissue, while advanced virtual planning techniques were employed for precise graft design and dental implant placement. The patients experienced substantial improvements in masticatory function, speech, and facial aesthetics. Utilizing autologous grafts minimized the risk of rejection and complications associated with foreign materials. The integration of virtual planning precision allowed customized solutions, reducing surgical duration and optimizing implant positioning. These 2 cases underscores the potential of combining autologous grafts with virtual planning precision and dental implants produced by additive manufacturing for mandible reconstruction.

UNASSIGNED: Systematic Review and Meta-Analysis.
UNASSIGNED: There has been an increasing trend in maxillofacial injuries associated with combat trauma. Within the maxillofacial complex, the mandible is the most likely structure to be damaged during combat. The structural deficits as a result can be reconstructed with many options. These include vascularised bone grafts (VBGs), non-vascularised bone grafts (NVBGs), alloplastic implants, reconstruction bars and distraction osteogenesis. This study aimed to determine the common modality and efficacy of mandibular reconstruction in combat trauma-related defects.
UNASSIGNED: A literature search was conducted on Pubmed, Prospero, Dynamed, DARE, EMBASE, COCHRANE and BMJ databases.
UNASSIGNED: A total of six articles met the inclusion criteria identifying 165 patients requiring mandibular reconstruction. Non-vascularised iliac bone graft (n = 137) was the most common method followed by ileac crest bone chips harvest using Dacron urethran osteomesh tray (n = 24) and frontoparietal grafts (n = 4). Meta-analysis of five out of six trials demonstrated an overall success rate of 85% (95% CI 79-90; I2 = 59%). A total of 13% (n = 22) of reconstructions failed either completely or partially and 21% (n = 34) of patients suffered postoperative complications.
UNASSIGNED: NVBGs are a practical, cost-effective and favourable method of war zone management of mandibular defects with success rates comparable to those reported in the civilian literature. However, general trauma principles take precedence to rule out life-threatening injuries. Due consideration of patient factors, surgical factors, and available resources are required in the first-line management of combat-related mandibular defects.

OBJECTIVE: Virtual surgical planning (VSP) is good for three dimensional reconstructions in maxillofacial surgery, but it is not problem-free completely especially when the resection margins cannot be affirmed in preoperative period. We aimed to obtain an ideal reconstruction with elaborating VSP to be prepared for adverse conditions during surgery and to proceed the oncological resections step- by- step with A, B, and C resection planes.
METHODS: Four patients undergoing multisegment VSP for the primary mandible malignancies were included in the study. The first resection margin was detected as plan A in VSP, and plans of B and C were also prepared considering the tumor- positive result of intraoperative frozen section procedure.
RESULTS: Following the tumor resection, margins were extended to the plan B in two patients, and plan C in one patient in accordance with the results of the frozen section procedure.Histogram comparison of the localizations of osteotomies in mandible and fibula, and positions of the implants were calculated at a confidence level of 95 % (p > 0.95) and mean difference was found -0.55 mm, while standard deviation was 1.76 mm.
CONCLUSIONS: Multisegment virtual surgical planning seems to achieve the optimal reconstruction with the staged resection preventing redundant removal of tumor- free structures like bone and teeth.

Secondary mandibular reconstruction using fibular free flaps (FFF) is a technical challenge for surgeons. Appropriate operation planning is crucial for postoperative quality control and is notably necessary for the (re-) achievement of a physiological condylar position, and the sensible expansion and shaping of the transplant. Computer-assisted planning may help to reconstruct mandibular defects in a patient-specific and precise manner. Herein, we present a newly-developed workflow for secondary mandibular reconstruction using FFF; it comprises digital planning and in-house manufacturing to perform precise secondary mandible reconstruction. This method utilizes a newly designed positioning device to ensure the precise positioning of the fibula segments in relation to each other and the mandibular stumps. The presented in-house-printed positioning device made it possible to achieve digital planning with high precision during surgery.

The aim of this study is to present a sequential strategy of soft-tissue, non-osteogenic distraction with a novel device, followed by microvascular bony reconstruction for severe cases of mandibular hypoplasia. The case of a 21-year-old woman with Goldenhar syndrome is presented, whose mandible remained severely hypoplastic despite previous attempts at distraction and was not suitable for further osteogenic distraction. Soft tissue deficiency and pin track scarring prevented free fibular transfers. A personalized distractor, anchored to the cranium and the mandibular symphysis, was designed to expand the soft tissues while allowing for physiological temporomandibular joint (TMJ) movement without compression forces. Internal distractors were placed along the osteotomies to prevent condylar luxation. After completion of the soft tissue distraction, the native mandible was resected except for the condyles and reconstructed with two free fibula flaps. This report represents the proof of concept of a sequential approach to severe lower face soft-tissue and bone deficiency, which preserves TMJ function and avoids the transfer of poorly matched skin to the face.

Oral cavity tumors are a prevalent cause of mandible reconstruction surgeries. The mandible is vital for functions like oralization, respiration, mastication, and deglutition. Current mandible reconstruction methods have low success rates due to complications like plate fracture or exposure, infections, and screw loosening. Autogenous bone grafts are commonly used but carry the risk of donor region morbidity. Despite technological advances, an ideal solution for mandible reconstruction remains elusive. Additive manufacturing in medicine offers personalized prosthetics from patient-specific medical images, allowing for the creation of porous structures with tailored mechanical properties that mimic bone properties. This study compared a commercial reconstruction plate with a lattice-structured personalized prosthesis under different biting and osseointegration conditions using Finite Element Analysis. Patient-specific images were obtained from an individual who underwent mandible reconstruction with a commercial plate and suffered from plate fracture by fatigue after 26 months. Compared to the commercial plate, the maximum von Mises equivalent stress was significantly lowered for the personalized prosthesis, hindering a possible fatigue fracture. The equivalent von Mises strains found in bone were within bone maintenance and remodeling intervals. This work introduces a design that doesn\'t require grafts for large bone defects and allows for dental prosthesis addition without the need for implants.

UNASSIGNED: Though the gold standard method for mandible reconstruction of the defect from segmental mandibulectomy is by osseous flap or graft, using reconstruction plates is still indicated in some cases. Traditionally, the plate is bended immediately after the segmental mandibulectomy by freehand. However, it\'s difficult to fit well to the original position of mandible, which may result in more complications. This study therefore aimed to investigate whether using prebent plates on computer-aided 3D printing models could reduce the complication rate.
UNASSIGNED: Patients who received mandible reconstruction by reconstruction plate from 2018 to 2022 were enrolled and evaluated in this study. The data, including demographics, indications for surgery, pre-existed preoperative and postoperative therapies, classification of defects, and postoperative outcomes were collected and analyzed.
UNASSIGNED: A total of 52 patients were enrolled in our study. The prebent group exhibited a significantly lower complication rate than that of the immediately bent group (P = 0.012). Other risk factors of plate complications included postoperative adjuvant radiotherapy (P = 0.017) and previous surgery (P = 0.047). The complication-free survival rate was also better in the prebent group in a 3-year follow-up period (P = 0.012).
UNASSIGNED: Prebent plates on computer-aided printing models proved to be an effective approach to reduce the complications for mandibular reconstruction in segmental mandibulectomy.

The posterior airway space (PAS) is a common site of passive obstructions with high morbidity. Surgical changes to the craniomandibular system may affect the PAS. Data regarding the effects of mandibular reconstruction using vascularized bone flaps on PAS are insufficient. This retrospective cohort study aimed to investigate changes in PAS after mandibular reconstruction.
Pre- and post-reconstructive computed tomography scans of 40 patients undergoing segmental mandibulectomy and mandibular reconstruction with deep circumflex iliac artery or fibula flaps were analyzed. Absolute differences in PAS geometry and relative trends of PAS volume changes were compared within the study population and between subgroups formed according to the extent of resection, timing and type of reconstruction, and presence of pre-reconstructive radiotherapy.
Irradiated patients were characterized by an increase in PAS volume after reconstruction. Absolute differences in total PAS volume after reconstruction were significantly different (p = 0.024) compared to non-irradiated patients. Reconstruction of central mandible segments resulted in decrease of the cross-sectional PAS areas. Absolute differences in middle cross-sectional PAS area after reconstruction were significantly different (p = 0.039) compared to non-central reconstructions. Patients who received radiotherapy were less likely to show a total PAS volume reduction after reconstruction (OR: 0.147; p = 0.007), with values adjusted for gender, age, body mass index, timing and type of reconstruction, and transplant length.
Mandibular reconstruction causes changes in PAS geometry. Specifically, reconstructions of central mandibular segments can lead to a reduction in the cross-sectional areas of PAS, and mandibular reconstructions in irradiated sites may cause an increase in PAS volume.

UNASSIGNED: With the development of computer-assisted surgery, digital guide plate was widely used in vascularized bone flap grafts for mandibular reconstruction. The purpose of this study was to design and manufacture a digital guide plate with drill-hole sharing for mandibular reconstruction and assess for surgical accuracy.
UNASSIGNED: 17 patients that required mandibular reconstruction using fibula free flap or iliac crest free flap were included in the study. The computed tomography (CT) data of the patient\'s mandible and pelvis or fibula were acquired preoperatively. A surgical simulation was then performed using computer-aided surgical simulation (CASS) technology based on above date, which allowed the design of two cutting guide and a repositioning guide for mandibular reconstruction. After surgery, the accuracy of reconstruction was evaluated by superimposing the postoperative image onto the preoperative image of mandible, recording the linear and angular deviation of landmarks, measuring the differences between the planned and actual outcomes.
UNASSIGNED: The osteotomy and repositioning of fibula or iliac crest segments were successfully performed as planned using surgical guides. The digital guide plate with drill-hole sharing showed excellent accuracy, When the iliac crest or the fibula free flap were used for mandibular reconstruction, the largest mean differences between the preoperative and postoperative were 1.11 mm and 2.8° or 1.3 mm and 3.87°.
UNASSIGNED: The digital guide plate with drill-hole sharing designed preoperatively provides a reliable method of for the mandibular reconstruction. This can assist surgeons in accurately performing osteotomy and repositioning fibula or iliac crest segments during the mandibular reconstruction.

BACKGROUND: Implant-supported dentures have become an essential means of restoring occlusal function after jaw reconstruction. Bone mineral density (BMD) may influence the success rate of implant denture restorations. This study aimed to explore whether the Hounsfield unit (HU) value can be used to monitor the changing trend of fibular BMD after jaw reconstruction.
RESULTS: A total of 54 patients who underwent maxillar/mandibular reconstruction with a fibula flap were included in this study. There was a significant correlation between the HU value and BMD at 1 week, 3 months, and 6 months after surgery, and both were significantly correlated with follow-up time. The difference between each pair of absorption rates (DAR) was less than 10% in 66.7% and 75.9% of patients at 3 and 6 months; however, the DAR was more than 20% in 12% and 13.8% of patients at 3 and 6 months, respectively.
CONCLUSIONS: There is a significant correlation between HU value and BMD. The HU value can be used to roughly reflect the fibular BMD changing trend in a group of patients as opposed to an individual, and the HU value is not equivalent to BMD.
BACKGROUND: ChiCTR, ChiCTR2300069661, retrospectively registered on 22 March 2023. Retrospectively registered, https://www.chictr.org.cn/showproj.html?proj=188953 .